ghostlymoron
Well-Known Member
I'd just note that it only takes a few minutes to recharge the starter battery. Although the starter draws a high current it's only for a few seconds unless you have have a problem with the engine.
Moving from 1,2,Both switch to VSR
- Thread starter fredrussell
- Start date
ghostlymoron
Well-Known Member
I've heard that argument before from a very experienced old sea dog. He forgot he'd selected 'both' and flattened both battery banks. Had to row back to shore, take the battery out of his car, row back, connect battery and start the engine.No problem in 27 years with 1,2,both switches on 4 boats so I'll stay the same
Sooner or later every normal person forgets I know I would when a VSR is cheap easy to fit and foolproof.
pandos
Well-Known Member
I have had a 12both switch on my boat for 15 years along with a blocking diode. Never in that time did I have an issue.
I am currently replacing my battery bank and simplifying my wiring whilst adding more fuses etc.
Pride of place will go to the 1 2 B switch but the diodes will be replaced with a cyrix, on Paul Rainbow's recommendation.
I really do not see what the problem with these devices is once some method of charging each bank is put in place.
The chances of depleting both banks without noticing that the switch is to both must be very slim and once it ocurred onece probably would not happen twice...
There is no other convenient way to harness the power of both banks if an issue arises which requires the extra oomph needed to bleed an old Volvo.
ghostlymoron
Well-Known Member
In my limited experience, 1-2-B-O switches are often located in inaccessible and difficult to see places so can easily be overlooked. I've never had a boat with one but have often sailed on boats with them and their skippers have frequently forgotten to change over after the starter battery has been re charged. I prefer to have an automatic system but of course it's your choice and it makes no odds to me what system you have. I merely offer up my own views and experience for consideration.
pandos
Well-Known Member
With blocking diodes or a cyrix, there is no need to do any switching, (both banks will be charged automaticlly) except to change which bank or combination is used to start.
In general this will be just the starter battery but if needed there is an easy option to add more battery power no harm to charging will occur if the skipper forgets to switch it back,
These switches seem to be misunderstood. (Maybe by me)
Tranona
Well-Known Member
Yes there is. A simple switch that connects the house bank to the starter circuit. Or a slightly more sophisticated solution to the whole charging splitting function use a BEP Marine switch cluster which a VSR, independent start and house plus a parallel switch all in one.
Don't follow the defence of a 1,2 both switch as once you have a split charge system it serves no useful purpose. Remember it came in when boats started to have 2 equal sized batteries and it was a useful way of using just one battery at a time. As soon as dedicated engine start batteries and big house banks came in (as you have) together with split charging it no longer served a useful purpose.
ghostlymoron
Well-Known Member
I had three separate isolators, bat 1, bat 2, and both. The latter didn't have the key left in.
Chris_Robb
Well-Known Member
here here! no corrosion either. I am forced to start from the engine battery as the Nasa BM1 battery Monitor (very good) has a 100 mp shunt which should not be used to start with! I have on many occasions by mistake.No problem in 27 years with 1,2,both switches on 4 boats so I'll stay the same
I have been happy for many years with 1,2 ,both. If starting from, scratch I might change.
One this to add is a proper battery Monitor, for use on your house banks. This will tell you all you need to know about whats going in and whats going out. Ignore the percentage charge on most. I use the Nasa BM1 which is probably the cheapest on the market but good - its 18 years old and no issues.
davierobb
Well-Known Member
I've used a 1.2.both switçhes and no issues. Always run it on 1 and switch to 2 on anchor, if I remember. We also have a victron 3 way charging splitter fitted which ensures, engine, domestic and windlass battery are always charged.
In the past I've used vsr but found them to be completely unreliable, regardless of cost. They are simply not designed to reliably handle high charge currents.
VSR also have a design flaw for marine use, scenario,
1 Engine battery charging at high rate,
2 Domestic battery with VSR connected is fully discharged.
3 When VSR senses a high enough voltage on engine battery it will put domestic battery into charging circuit.
4 This may reduce the voltage on the engine battery and will cause the VSR to drop the domestic battery out the charging loop.
5 The engine battery voltage will rise as it is being charged at a reasonable rate again.
Step 3, 4 and 5 will be repeated until either the domestic battery has enough charge to prevent overloading tye alternator or the VSR contact burn out.
This tends to be more of an issue on low output alternators. However contacts on incorrectly speced VSR may burn out due solely to the high charge current drawn by a discharged battery.
Some will say that they use VSR with no issue, most likely you have a well designed system and don't accidenly discharge batteries.
In the past I've used vsr but found them to be completely unreliable, regardless of cost. They are simply not designed to reliably handle high charge currents.
VSR also have a design flaw for marine use, scenario,
1 Engine battery charging at high rate,
2 Domestic battery with VSR connected is fully discharged.
3 When VSR senses a high enough voltage on engine battery it will put domestic battery into charging circuit.
4 This may reduce the voltage on the engine battery and will cause the VSR to drop the domestic battery out the charging loop.
5 The engine battery voltage will rise as it is being charged at a reasonable rate again.
Step 3, 4 and 5 will be repeated until either the domestic battery has enough charge to prevent overloading tye alternator or the VSR contact burn out.
This tends to be more of an issue on low output alternators. However contacts on incorrectly speced VSR may burn out due solely to the high charge current drawn by a discharged battery.
Some will say that they use VSR with no issue, most likely you have a well designed system and don't accidenly discharge batteries.
VicS
Well-Known Member
ITYWF that a modern microprocessor controlled VSR, such as a VIctron Cyrix, will not rapidly cycle in the way you describe
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pandos
Well-Known Member
I think the issue with 12bs arise if they are used primarily to choose the battery being charged.
If used to select the source of power for starting, it serves the usefull purpose of a parallel switch and an off switch for the engine battery and conviently it does this all in one unit with little prospect of getting things wrong.
Whether you use a Cyrix, diodes or a VSR along with it is probably a matter for personal choice, I agree one must have some automatic means of distributing the charging capacity.
I noticed this about the BM1 after 15 years of ocassionally using the house bank to start, also suffered no I'll effects.
In the search for some guidance I read the manual last week and serendipitously discover that the BM1 will also monitor the voltage on a second battery bank.
I will be finishing off my new installation tomorrow with loads of fuses and the original 12B and BM1. With many meters less of heavy gauge cabling.(I will be adding a Cyrix)
Tranona
Well-Known Member
Always worth reading the manual - the NASA ones are simple and succinct. Does away with the need for voltmeters in the switch panel which were so popular (and space consuming) at one time. I am starting from scratch on my project boat and will do the same as I did over 25 years ago with a BEP marine cluster and a BM1. Simplest and cheapest way of managing charging, control and monitoring. Only added complication is charging the forward battery for the windlass which will be done with a Sterling B2B from the Red Flash start battery. 1,2,B for the skip.
Tranona
Well-Known Member
Never experienced any of this over 25 years using a VSR, much of the time with a 35amp alternator on a Yanmar 1GM and a BEP VSR
Why raise problems that might occur when to use your own words in a well designed system and a quality VSR they do not happen?
pandos
Well-Known Member
Agree the manual is worth reading, at least twice..
Suggest you look at a Cryrix as an alternative to a VSR.
Why not wire the windlass back to the house bank?
pandos
Well-Known Member
Those problems do occur, even in well designed systems.
Buck Turgidson
Well-Known Member
Correct. The hysteresis problem as described is resolved with timing schedules built into the VSR. it's 2022 not 1980.
ghostlymoron
Well-Known Member
I thought a Cyrix was a VSR.
pandos
Well-Known Member
I Suppose it is a kind of one, but more advanced. It senses both batteries and Victron call it a battery combiner...
PaulRainbow
Well-Known Member
It is a dual sensing VSR, ie it senses voltage from both batteries/banks.
Tranona
Well-Known Member
Because of the cost of heavy wiring and I bought the Sterling on here for a modest sum - and the forward battery is an almost new one, well installed. Try to work with what I have which may not always be the same as starting from scratch. The bow battery was originally charged from a solar panel which I removed because it (and the set of davits it was mounted on) is not needed for the way I shall use the boat.